package view;


/**
 * interface to mark as Observable
 *
 */
public interface Observable 
{
 /**
  * register observer
  * @param observer the observer to register
  */
 public void registerObserver(Observer observer);
 
 /**
  * unregister observer
  * @param observer the observer to unregister
  */
 public void unRegisterObserver(Observer observer);

 /**
  * notify observers
  * @param action the action
  */
 public void notifyObservers(String action);

}
